indicatrix
/ˌɪndɪˈkeɪtrɪks/(亦作optical indicatrix)
noun
(pl. indicatrices /-trɪsiːz/)
- Crystallography an imaginary ellipsoidal surface whose axes represent the refractive indices of a crystal for light following different directions with respect to the crystal axes【晶体】折射率椭球。
词源
late 19th cent.: modern Latin, feminine of Latin indicator 'something that points out'.